Premium threaded connection and method for making same

ABSTRACT

A method of converting a tubular having NC46 connections to CET®43 connections. A method of applying a CET®43 thread to a pin connection or a box connection or both. A box connection and a pin connection of the tubular are machined and a CET®43 thread applied to the box connection and the pin connection.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.15/691,922, filed Aug. 31, 2017, which claims the benefit of priority ofU.S. Patent Application No. 62/470,541 Filed Mar. 13, 2017. Both ofthese prior applications are incorporate herein by reference in theirentirety.

FIELD

The present disclosure relates generally to oil and gas tubulars. Moreparticularly, the present disclosure relates to premium threading of oiland gas tubulars.

BACKGROUND

In the field of earth rock drilling, completion, and servicing, forexample to produce oil and/or gas from a subterranean reservoir, theterm “tubular” is often used to describe the various pipes. TheSchlumberger® Oilfield Glossary at http://www.glossary.oilfield.slb.comdescribes “tubular” as a generic term pertaining to any type of oilfieldpipe, such as drill pipe, drill collars, pup joints, casing, productiontubing and pipeline. The related term “connection” is described as anythreaded or nonthreaded union or joint that connects two tubularcomponents. The present disclosure relates to threadedconnectors/connections for tubulars.

A wide variety of threaded connections are available for tubulars, whichmay be general purpose connections or premium threaded connections,depending on the operating conditions.

One general purpose threaded connection is NC46, in accordance withAmerican Petroleum Institute (API) 7-1, Specification for Rotary DrillStem Elements and API 7-2, Specification for Threading and Gauging ofRotary Shouldered Thread Connections. A tubular/threaded connectionmeeting the NC46 standard will meet a number of technical specificationsin terms of dimensions and operating parameters.

General purpose tubulars have been around for years, but as wellboreoperations have evolved, higher demands are placed tubulars andconnections. Tubulars can be subjected to high temperatures andpressures and other extreme operating conditions, such as high torsionalstrength, for example in horizontal drilling or hydraulic fracturingoperations, and often tubulars having premium threaded connections arerequired or preferred.

It is, therefore, desirable to provide a premium threaded connector andmethod for making the premium threaded connector.

SUMMARY

It is an object of the present disclosure to obviate or mitigate atleast one disadvantage of previous threaded connections. One aspect ofthe present disclosure is that one can convert relatively commontubulars having NC46 connections to a higher value, high performancetubular having premium connections, such as CET®43 threads suitable fordemanding applications such as horizontal drilling or hydraulicfracturing. Another aspect of the present disclosures is that CET®43threads provide distinct functional advantages over other threads.CET®43 threads may be applied to new tubulars, used tubulars, or may befreshly cut into metal blanks to be used with tubulars.

In an embodiment disclosed, the threads disclosed herein may be appliedto an integral connection (e.g. pin-box) or a threaded and coupledconnection (e.g. pin-coupling-pin, as in oil country tubular goods(OCTG)). The threads disclosed herein may be applied to a new tubular ora recycled or re-used or repurposed tubular as described herein.

In a first aspect, the present disclosure provides a method includingproviding a tubular having an NC46 box connection and an NC46 pinconnection, reducing a box outer diameter of the NC46 box connection andenlarging a box inner diameter of the NC46 box connection to provide aprepared box connection, applying a box premium thread to the preparedbox connection, reducing a pin outer diameter of the NC46 pin connectionand enlarging a pin inner diameter of the NC46 pin connection to providea prepared pin connection, and applying a pin premium thread to theprepared pin connection, wherein the tubular is provided with a boxpremium connection and a pin premium connection.

In an embodiment disclosed, the box premium thread comprises a CET®43box thread, wherein the pin premium thread comprises a CET®43 pinthread, and wherein the box premium connection and the pin premiumconnections are CET®43 connections.

In an embodiment disclosed, the method further includes heating ahardband portion of the NC46 box connection to about 950 degreesFahrenheit prior to reducing the outer diameter.

In an embodiment disclosed, the method further includes phosphating theCET®43 connections.

In an embodiment disclosed, the method further includes applying a makeand break process to the CET®43 connections.

In an embodiment disclosed, the CET®43 connections have an outerdiameter of about 5.375″ and the CET®43 connections have an innerdiameter of about 3″.

In an embodiment disclosed, the CET®43 box threads have a pitch of about0.25″ (4 TPI), an angle of about 60 degrees, a crest to root height ofabout 0.092500″, a taper of about 1.5 in/ft, a crest width of about0.067″, and a root width of about 0.076″.

In an embodiment disclosed, the CET®43 pin threads have a pitch of about0.25″ (4 TPI), an angle of about 60 degrees, a crest to root height ofabout 0.092504″, a taper of about 1.5 in/ft, a crest width of about0.076″, and a root width of about 0.067″.

In an embodiment disclosed, the tubular is previously used or isreconditioned.

In an embodiment disclosed, the method further includes performing awellbore operation using the tubular having CET®43 connections.

In an embodiment disclosed, the wellbore operation comprises horizontaldrilling or hydraulic fracturing or both.

In a further aspect, the present disclosure provides a method ofconverting a tubular having NC46 connections to CET®43 connections,including providing the tubular, having an NC46 box connection and anNC46 pin connection, heating a hardband portion of the NC46 boxconnection to about 950 degrees Fahrenheit and reducing a box outerdiameter of the NC46 box connection, enlarging a box inner diameter ofthe NC46 box connection, wherein a prepared box connection is provided,applying a CET®43 box thread to the prepared box connection, wherein theCET®43 threads have a pitch of about 0.25″ (4 TPI), an angle of about 60degrees, a crest to root height of about 0.092500″, a taper of about 1.5in/ft, a crest width of about 0.067″, and a root width of about 0.076″,reducing a pin outer diameter of the NC46 pin connection, enlarging aninner diameter of the pin connection, wherein a prepared pin connectionis provided, and applying a CET®43 pin thread to the prepared pinconnection, wherein the CET®43 threads have a pitch of about 0.25″ (4TPI), an angle of about 60 degrees, a crest to root height of about0.092504″, a taper of about 1.5 in/ft, a crest width of about 0.076″,and a root width of about 0.067″.

In an embodiment disclosed, the CET®43 connections have an outerdiameter of about 5.375″ and the CET®43 connections have an innerdiameter of about 3″.

In a further aspect, the present disclosure provides a method to recut atubular having CET®43 threaded connections, including providing thetubular having CET®43 threaded connections; and re-cutting CET®43threads, wherein a remaining tong length exceeds a predetermined minimumtong length after re-cutting.

In a further aspect, the present disclosure provides a CET®43 boxconnection for a first tubular, including a box shoulder stop, a boxshoulder bearing surface, a face bearing surface, a face stop, andCET®43 box threads extending between the face bearing surface and thebox shoulder bearing surface, wherein the CET®43 box connection isadapted to mate with a CET®43 pin connection of a second tubular,wherein the box shoulder bearing surface is adapted to retain acorresponding nose bearing surface of the CET®43 pin connection.

In an embodiment disclosed, the face bearing surface is adapted toretain a corresponding pin shoulder bearing surface of the CET®43 pinconnection.

In an embodiment disclosed, the face stop and the pin shoulder stop areadapted to abut, the nose and the box shoulder stop are adapted to abut,or both.

In an embodiment disclosed, an annular space between the box shoulderbearing surface and the nose bearing surface defines a first bearinggap.

In an embodiment disclosed, an annular space between the tail bearingsurface and the face bearing surface defines a second bearing gap.

In an embodiment disclosed, the first bearing gap or the second bearinggap or both are in the range of about 0.01″ to about 0.10″. In anembodiment disclosed, the first bearing gap or the second bearing gap orboth are about 0.020″.

In an embodiment disclosed, the CET®43 box threads have a pitch of about0.25″ (4 TPI), an angle of about 60 degrees, a crest to root height ofabout 0.092500″, a taper of about 1.5 in/ft, a crest width of about0.067″, and a root width of about 0.076″.

In a further aspect, the present disclosure provides a CET®43 pinconnection for a first tubular, including a nose, a nose bearingsurface, a pin shoulder bearing surface, a pin shoulder stop, and CET®43pin threads extending between the nose bearing surface and the pinshoulder bearing surface, wherein the CET®43 pin connection is adaptedto mate with a CET®43 box connection of a second tubular, wherein thenose bearing surface is adapted to be retained by a mating box shoulderbearing surface of the CET®43 box connection.

In an embodiment disclosed, the pin shoulder bearing surface is adaptedto be retained by a mating face bearing surface of the CET®43 boxconnection.

In an embodiment disclosed, the face stop and the pin shoulder stop areadapted to abut, the nose and the box shoulder stop are adapted to abut,or both.

In an embodiment disclosed, an annular space between the box shoulderbearing surface and the nose bearing surface defines a first bearinggap.

In an embodiment disclosed, an annular space between the tail bearingsurface and the face bearing surface defines a second bearing gap.

In an embodiment disclosed, the first bearing gap or the second bearinggap or both are in the range of about 0.01″ to about 0.10″. In anembodiment disclosed, the first bearing gap or the second bearing gap orboth are about 0.020″.

In an embodiment disclosed, the CET®43 pin threads have a pitch of about0.25″ (4 TPI), an angle of about 60 degrees, a crest to root height ofabout 0.092504″, a taper of about 1.5 in/ft, a crest width of about0.076″, and a root width of about 0.067″.

In a further aspect, the present disclosure provides a tubular havingCET®43 connections, comprising a CET®43 box connection and a CET®43 pinconnection.

Other aspects and features of the present disclosure will becomeapparent to those ordinarily skilled in the art upon review of thefollowing description of specific embodiments in conjunction with theaccompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present disclosure will now be described, by way ofexample only, with reference to the attached Figures.

FIG. 1 is a portion of tubulars having NC46 pin connections and NC46 boxconnections.

FIG. 2 is a portion of a tubular having a NC46 pin connection, with aportion of hardbanding removed.

FIG. 3 is the NC46 pin connection of FIG. 2, with the hardbandingremoved and an identification groove applied.

FIG. 4 is the NC46 pin connection of FIG. 3, before the inner diameteris enlarged.

FIG. 5 is the NC46 pin connection of FIG. 4, after the inner diameterhas been enlarged.

FIG. 6 is the NC46 pin connection of FIG. 5, having a prepared pinconnection, before threading.

FIG. 7 is the NC46 pin connection of FIG. 6, with the NC46 pinconnection converted to a CET®43 pin connection.

FIG. 8 is a drawing of a CET® 43 pin connection.

FIG. 9 is a detail of FIG. 8.

FIG. 10 is a detail of FIG. 8.

FIG. 11 is a portion of a tubular having an NC46 box connection.

FIG. 12 is the NC46 box connection of FIG. 11, being heated.

FIG. 13 is the NC46 box connection of FIG. 12, after the hardbanding hasbeen removed and the outer diameter has been reduced.

FIG. 14 is the NC46 box connection of FIG. 13, with the NC46 boxconnection converted to a CET®43 box connection.

FIG. 15 is a drawing of a CET® 43 box connection.

FIG. 16 is a detail of FIG. 15.

FIG. 17 is a detail of FIG. 15.

FIG. 18A is a pin connection of FIGS. 8-10 and FIG. 18B is a boxconnection of FIGS. 15-17, aligned for connection.

FIG. 19 is the box connection and the pin connection of FIG. 18,connected.

FIGS. 20 to 22 are details of FIGS. 8 to 10.

FIGS. 23 to 25 are details of FIGS. 15 to 17.

DETAILED DESCRIPTION

Generally, the present disclosure provides a method and system forproviding a tubular having CET®43 connections, and in a particularembodiment, converting a tubular from NC46 connections to CET®43connections.

Referring to FIG. 1, a receiving inspector inspects a tubular 10 and anyidentification marks, such as work order numbers, serial numbers,purchase order numbers, or anything stenciled or stamped onto thetubular 10. Serial numbers are recorded and written back on the tubular10 on both sides. The tubular 10 may have an NC46 box connection 20, anNC46 pin connection 30, or both.

In an embodiment disclosed, the materials must be within a specifiedyield strength, for example 130 ksi minimum.

In an embodiment disclosed, NC46 refers to American Petroleum Institute(API) 7-1, Specification for Rotary Drill Stem Elements and API 7-2,Specification for Threading and Gauging of Rotary Shouldered ThreadConnections or other applicable specification, and specifically APINumbered Connection 46 (NC46), for example having 4 threads per inch(TPI), 2″ taper per foot (TPF), and thread gauge V-0.038R.

The tubular 10 is loaded onto an inbound rack where the process ofconverting the tubular from NC46 connections to CET®43 connectionsbegins.

PIN Connection

Referring to FIG. 2, any hardbanding 40 is removed (NC46 pin connection30 shown), for example by computer numeric control (CNC) lathe ormachining tool. The hardbanding 40 may be removed, for example, using aCDN43 insert. The length 36 (see FIG. 1) may be checked. The CNCcontrolled lathe or machining tool then makes two additional passes tomachine the outer dimension to comply with print specifications. Theouter diameter 32 of the NC46 pin connection is machined to provide areduced outer diameter 50 (the hardbanding 40 shown only partiallyremoved). The particular example tubular 10 shown, calls for a CET®43pin connection 80 having a 5.375″ outer diameter, which the CNC lathe ormachining tool is programed to do using an SNMG 644 insert.

Referring to FIG. 3, the outer diameter 32 of the NC46 pin connection 30has been machined to provide the reduced outer diameter 50 (for example5.375″), and an identification groove 60 is provided (e.g. machined) ata predetermined location from taper 38 (for example 2 inches from an 18degree taper shown). A DNMG 432 insert is used in this process. Themachine operator then inspects the identification groove 60 to confirmcompliance with print specifications (normally 0.0625″ deep).

Referring to FIG. 4, once the reduced outer diameter 50 has beenreduced, for example by machining, the tubular 10 may be kicked out tothe next CNC machine. While on the rack, the machine operator maymeasure the inner diameter 34 of the NC46 pin connection 30 anddetermine which program to run to enlarge the inner diameter 34, forexample by boring. This particular NC46 pin connection 30 has a 2.750″inner diameter and must be enlarged or bored out to 3″ inner diameter tomeet the requirements of a CET®43 pin connection 80.

Referring to FIG. 5, the CNC machine, using a 2.500″ boring bar with anSNMG644 insert, enlarges the inner diameter 34 of the pin connection 30to provide a enlarged inner diameter 70 to meet print specifications. Ifit does not meet specifications, the operator does one skim pass to makeit compliant. After this process, a drift is inserted 4 feet. If thedrift comes back clean, the enlarging process is complete. For example,for a 3″ enlarged inner diameter 70, a 2.875″ drift may be used.

Referring to FIG. 6, once the reduced outer diameter 50 and the enlargedinner diameter 70 are complete, the machine operator may ensure thereduced outer diameter 50 and the enlarged inner diameter 70 areconcentric, and the prepared pin connection 75 is ready for thethreading process. While on the rack, the enlarged inner diameter 70 isvisually inspected to see if there is any debris or shavings left overfrom the boring process. The tubular 10 is then blown out to ensure thatit is clean. The pin connection 30 is prepared and is ready for CET®43threads to be applied. A face off tool using an CNMG543 insert is usedfor the first cut. A rough profile cut is made using an VNMG432 insertis used to cut the profile to print specifications. Threads are cutusing an LDS544 insert. Sharp corners of imperfect threads from start tofull form threads by machining are cut using an NRK54 insert. The flatwidth must not exceed crest width. The inner diameter break is cut usingan CNMG432 insert. The machine operator inspects, using a CET®43 ringgage, that the threads are machined to print specifications. Gagestandoff, pin and nose cylinder diameter, bevel diameter and pin lengthdimensions are recorded on inspection reports and any non-conformance isreported to quality control (QC) and dispositioned accordingly. Anyrequired stamping is applied after the pin thread is inspected (e.g.serial number, hardbanding stamp, connection, etc.).

Referring to FIG. 7, the prepared pin connection 75 has been threadedwith CET®43 threads to provide a CET®43 pin connection 80. CET®43 pinthread protectors (not shown) may be applied.

PIN Connection CET®43 Threads

Referring to FIGS. 7-10, and 18-19, a CET®43 pin connection 80 is shown,of a specific size. However, CET®43 threads may be applied in differentsizes.

In an embodiment disclosed, the CET®43 threads provide 5¼ turns tomake-up, have 170-200% of the torsional strength of American PetroleumInstitute (API) connections, and may be applied to various tubulars,including drill pipe, heavy-weight drill pipe and collars for use onwork strings, slimhole drillstrings and frac strings.

The CET®43 threads provide high torque, high threads per inch (TPI),reduced shoulder and nose length.

The CET®43 threads may be applied to a wide variety of tubular/pipesizes, including but not limited to 4½″, 5″, 5½″, 6⅝″, and 7⅝″ pipeouter diameter.

In an embodiment disclosed, the CET®43 connection has an outer diameterof 5.375″, an inner diameter of 3″, a recommended make-up torque of24,400 ft-lbs, a tensile yield strength of 805,800 lbs, and a torsionalyield strength of 37,500 ft-lbs.

Referring to FIG. 8, the CET®43 pin connection 80 has a nose bearingsurface 120 of relatively short length, tapered thread 130, and a pinshoulder bearing surface 140 of relatively short length. In anembodiment disclosed, the length of the nose bearing surface 120 isabout 0.5″. In an embodiment disclosed, the length of the pin shoulderbearing surface 140 is about 0.5″ or less (measured from the pinshoulder stop 150 to the flank of the first full depth thread). In anembodiment disclosed, the distance between the nose 110 and the pinshoulder stop 150 is about 4.5″. In an embodiment disclosed, thediameter of the nose bearing surface 120 is about 3.876″. In anembodiment disclosed, the diameter of the pin shoulder bearing surface140 is about 4.522″.

Referring to FIG. 9, in an embodiment disclosed the pin shoulder bearingsurface 140 includes a reduced clearance portion 145 adapted to form atight fit with the mating face bearing surface 170 of the mating CET®43box connection 100 (see FIG. 15). In an embodiment disclosed, the tightfit is an interference fit. In an embodiment disclosed, the reducedclearance portion 145 has a length of about 0.125″.

Referring to FIG. 10, in an embodiment disclosed the tapered threads 130have a pitch of about 0.25″ (4 TPI), an angle of about 60 degrees, acrest to root height of about 0.092504″ and a taper of about 1.5 in/ft.In an embodiment disclosed the crest width is about 0.076″ and the rootwidth is about 0.067″. In an embodiment disclosed the tapered threads130 conform to thread gauge V-0.076 thread form design data.

BOX Connection

Referring to FIG. 11, a receiving inspector inspects the outer diameter22, inner diameter 24, hardbanding 40, and identification marks (if any)of the tubular 10. The length 26 of the threads may be checked. Thetubular 10 has at least one NC46 box connection 20.

The tubular 10 is loaded onto an inbound rack where the process ofconverting the tubular from NC46 connections to CET®43 connectionsbegins.

Referring to FIG. 12, the hardbanding 40, if any, is heated to about950° Fahrenheit by applying heat 90. This process is only necessary onthe box end, as the hardbanding 40 is longer (three 1″ bands on the boxend as opposed to two 1″ bands on the pin end). The heating softens thehardbanding 40 enough to enable it to be cut using an CBN43 insert. TheCNC machine then makes two additional passes to machine to printspecifications to provide a reduced outer diameter 50. This particularexample CET®43 box connection 100 calls for a 5.375″ outer diameter,which the CNC is programed to do using an SNMG 644 insert.

Referring to FIG. 13, the machine operator visually inspects the innerdiameter 24 on the box end connection for shavings and debris. Themachine operator visually inspects the outer diameter and uses an outerdiameter micrometer set to 5.375″ to verify the reduced outer diameter50 meets the print specifications, to provide a prepared box connection95.

A face off tool using an CNMG543 insert is used for the first cut. A 2″boring bar using an CNMG431 insert is used to bore the inner diameter 34to print specifications. Threads are cut using a threading bar with anLDS544 insert. Sharp corners of imperfect threads from start to fullform threads by machining are cut using an NLK54 insert. The flat widthmust not exceed the crest width. The inner diameter break is cut usingan CNMG432 insert. The machine operator inspects the tapered threads130, using a CET®43 plug gage, to ensure that the threads are machinedto print specifications. The gage standoff, counter bore diameter, innerdiameter, bevel diameter and box thread depth dimensions are recorded oninspection reports and any non-conformance is reported to qualitycontrol (QC) and dispositioned accordingly. CET®43 box thread protectorsare applied and the pipe or tubular 10 is ready for the next step.

Referring to FIG. 14, a CET®43 thread has been applied to the preparedbox connection 95 and a CET®43 box connection 100 is provided.

BOX Connection CET®43 Threads

Referring to FIGS. 14-19, a CET®43 box connection 100 is shown, of aspecific size. However, CET®43 threads may be applied in differentsizes.

In an embodiment disclosed, the CET®43 threads provide 5¼ turns tomake-up, have 170-200% of the torsional strength of American PetroleumInstitute (API) connections, and may be applied to various tubulars,including drill pipe, heavy-weight drill pipe and collars for use onwork strings, slimhole drillstrings and frac strings.

The CET®43 threads provide high torque, high threads per inch (TPI),reduced shoulder and nose length.

The CET®43 threads may be applied to a wide variety of pipe sizes,including but not limited to 4½″, 5″, 5½″, 6⅝″, and 7⅝″ pipe outerdiameter.

In an embodiment disclosed, the CET®43 connection has an outer diameterof 5.375″, an inner diameter of 3″, a recommended make-up torque of24,400 ft-lbs, a tensile yield strength of 805,800 lbs, and a torsionalyield strength of 37,500 ft-lbs.

Referring to FIG. 15, in an embodiment disclosed, the CET®43 boxconnection 100, extends between a face stop 160 and a box shoulder stop200, and includes a face bearing surface 170, tapered thread 180, and abox shoulder bearing surface 190. In an embodiment disclosed, the facebearing surface is about 0.625″ wide. In an embodiment disclosed, thebox shoulder bearing surface 190 is about 0.375″ wide. In an embodimentdisclosed, it is about 4.125″ or more from the face stop 160 to theflank of the first full depth thread (proximate the box shoulder stop200. In an embodiment disclosed, it is about 4.5″ between the face stop160 and the box shoulder stop 200. In an embodiment disclosed, thereduced outer diameter 50 is about 5.125″. In an embodiment disclosed,the counterbore/face bearing surface 170 has a diameter of about 4.617″.In an embodiment disclosed, the box shoulder bearing surface has adiameter of about 3.973″.

Referring to FIG. 16, in an embodiment disclosed, the CET®43 boxconnection 100 includes an enlarged guide portion 175 between the facestop 160 and the face bearing surface 170. In an embodiment disclosed,the enlarged guide portion is about 0.125″ wide.

Referring to FIG. 17, in an embodiment disclosed the tapered threads 180have a pitch of about 0.25″ (4 TPI), an angle of about 60 degrees, acrest to root height of about 0.092500″ and a taper of about 1.5 in/ft.In an embodiment disclosed the crest width is about 0.067″ and the rootwidth is about 0.076″. In an embodiment disclosed the tapered threads130 conform to thread gauge V-0.076 thread form design data.

Zinc Phosphate

The tubular, having a CET®43 box connection 100 and a CET®43 pinconnection 80 may be subject to a surface treatment, such as a zincphosphate process. The purpose of this process is to ensure the tubular10 or tool joint has the correct structure and thickness, unit weightper area, adheres and imparts the correct lubricity for repeated threadseals and make/breaks under torque without galling. Once both the pinand box are threaded, they are cleaned. The parts must be clean of metalworking fluid, grease, oil, rust, paint, and any other contaminant priorto phosphate coating. This can be done using flow over cleaning stationsor brush and bucket cleaning using alkaline detergents. Alternativemethods include abrasive blasting or wire wheel buffing. After cleaningthe CET®43 pin connection 80 and the CET®43 box connection 100, they arerinsed with fresh water to remove any detergent residue. Conversely, anyblasting media should be blown out as well to avoid any crosscontamination into the zinc phosphate solution. After cleaning andrinsing, the CET®43 pin connection 80 and box connection 100 arepositioned at the application area (rolling rack with an immersion tankcontaining a suitable zinc phosphate solution, such as Solucoat 5027J,which is a liquid concentrated zinc phosphate for immersion, spray orflow coat processing of iron, steel, and zinc. The zinc phosphate willimpart a tight crystalline coating and can be used as a base for paint,or supplementary oil finish). The operator ensures the zinc phosphate iscontained during the coating process. The tubular 10 is elevated at therear to drain the phosphate back into the heated tank. The operatorensures the application nozzles wet the entire tubular 10 andconnections. Any phosphate water break will slow the reaction time downor force the operator to rotate the part for complete saturation. Theoperator ensures the phosphate solution is not applied using too muchpressure. Too much pressure will blow the phosphate solution/coating offbefore it has a chance to root. Pumps must be sized for high volumeflood instead of pressure. If the phosphate splashes back at theoperator, the pressure is too high for successful coating. Three thingsare most important when processing zinc phosphate: phosphate solutionconcentration, solution temperature, and time. These parameters arealtered slightly to adjust for the flow over application technique. Oncethe CET®43 pin connection 80 and the CET®43 box connection 100 are flowcoated in a Solucoat 5027J solution (20 to 30 min at 175+/−25° F.), theconnections are ready for a connection make and break process and finalinspection.

Connection Make and Break

All make and break shall be done after phosphating or other approvedsurface treatment. The operator removes and cleans the thread protectorssince they may be re-used but possibly without any or a different threadcompound. The threads and torque shoulder(s) are pre-cleaned, ensuringall oil, dust and other contaminates are removed. The operatorpre-inspects threads and shoulders for nicks and burrs. Minor ones canbe removed with a deburring tool, file or honing stone. A coating of athread compound is applied evenly to both the pin and box connectionmake-up shoulders and threads using a stiff bristle brush to spread andwork in a thin uniform coating.

Each of the CET®43 pin connection 80 and the CET®43 box connection 100are carefully stabbed and made up hand tight to avoiding cross threadingor damage to threads and shoulders. The hand tight assembled componentsare placed in the make and break unit and secured with jaws in theheadstock, ensuring the tong jaws are not on any raised hardbanding andare positioned at the center of the tong space and at least 2 inchesfrom the box shoulder bearing surface 190/box shoulder stop 200 regionso as to avoid crushing or other damage. Avoid positioning the jaws atany location where mill identification markings/stamping will beremoved.

Power is then applied to make up a connection between a CET®43 pinconnection 80 and a CET®43 box connection 100, at a maximum of 60 RPM.

Make and Break three times as follows:

1. Make to 60% of nominal make up torque (MUT) with specified plus/minustolerance.

Break (monitor breakout torque does not exceed 90% MUT).

2. Make to 80% of nominal MUT with specified plus/minus tolerance.

Break (monitor breakout torque does not exceed 90% MUT).

3. Make to 100% of nominal MUT with specified plus/minus tolerance.

Break (monitor breakout torque does not exceed 90% MUT).

In an embodiment disclosed, the box diameter is substantially 6.25″, thepin inner diameter is 3.25″, and the required torque is 42,400 ft-lbs.

The operator then separates the box connection and the pin connectionand cleans threads and torque shoulders. An inspection for any pinstretch or box swelling is conducted. If there is any indication of pinstretch or box swelling or both, further quality control (QC) isconducted to dimensional gage the suspect tool joint, including checkingbox outer diameter, pin length and box depth on double shoulderedconnections, etc.

Inspection of threads for galling or other damage is done.

Inspection torque shoulders for pickup or tearing. The primary shouldersshould have a finish of 150 or less and any scratches across theshoulder are not allowed.

The secondary torque shoulder is not a seal, it is a mechanical stop.The pin nose must be free of raised metal or other imperfections thatcould prevent proper make up or cause galling. Pin nose damage can berepaired with a hand file. The tubular 10 is then ready for finalinspection.

Final Inspection

On good connections: The operator cleans threads and torque shouldersproperly and thoroughly coated with an environmentally approved (i.e.“Green”) thread storage compound if specified. Heavy duty threadprotectors are cleaned and reapplied. “MB” is stamped on the taperedshoulders of box and pin using ¼″ low stress stamps. The operator thenlightly grinds the raised tong marks flush to outer diameter of tongspace.

On galled or otherwise damaged connections: A non-conformance report(NCR) is created, and a number or other unique inspection serial numberis applied to the tong space, marking the type of damage on the tongspace with permanent marker. A record of the type of damage versusNCR/serial number is made on an inspection report. Light oil is appliedand a clean thread protector is installed to protect the connectionuntil it can be further evaluated or reworked. The non-conformingtubular is placed in a separate location. Inspection reports andcompleted work orders are turned over to purchasing to complete theprocess.

Joint

Referring to FIGS. 18A, 18B and 19, the CET®43 pin connection 80 has anose 110 and a relatively short nose bearing surface 120. A taperedthread 130 extends from the nose bearing surface 130 to a pin shoulderbearing surface 140, and the CET®43 pin connection 80 ends with a pinshoulder stop 150.

The CET®43 box connection 100 has a face stop 160 and a relatively shortface bearing surface 170. A tapered thread 180 extends from the facebearing surface 170 to a box shoulder bearing surface 190, and theCET®43 box connection 100 ends with a box shoulder stop 200.

In an embodiment disclosed, the bearing surfaces may be about ½″ wide,including the nose bearing surface 120 (and the mating box shoulderbearing surface 190), the pin shoulder bearing surface 140 (and themating face bearing surface 170), or both.

Referring to FIG. 19, when the CET®43 pin connection 80 and the CET®43box connection 100 are joined and tightened (e.g. torqued), the nosebearing surface 120 and the mating box shoulder bearing surface 190 arealigned and mated, the pin shoulder bearing surface 140 and the matingface bearing surface 170 are aligned and mated, the nose 110 and the boxshoulder stop 200 abut, and the face stop 160 and the pin shoulder stop150 abut.

In an embodiment disclosed, an annular gap between the bearing surfaces,including annular bearing gap 210 between the nose bearing surface 120and the mating box shoulder bearing surface 190, and annular bearing gap210 between the pin shoulder bearing surface 140 and the mating facebearing surface 170, or both, are relatively small. In an embodimentdisclosed, the annular bearing gap 210 or the annular bearing gap 220 orboth are between about 10 to about 100 thousandths of an inch. In anembodiment disclosed, the annular bearing gap 210 or the annular bearinggap 220 or both is about 0.020 inches. This relatively small gap allowsfor transfer of at least a portion of the load/stresses (e.g. torque)from the CET®43 box connection 100 to the CET®43 pin connection 80 (orvice-versa) though the bearing surfaces, which lowers the stress on thethreads. The CET®43 pin connection 80 is at least partially restrainedor constrained by the CET®43 box connection 100 (i.e. the nose bearingsurface 120 and the pin shoulder bearing surface 140 of the CET®43 pinconnection 80 are constrained by the corresponding box shoulder bearingsurface 190 and face bearing surface 170 of the CET®43 box connection100). When rotational torque is applied to the tubular 10, the torque isspread among the tapered threads as well as the bearing surfaces. As aresult, the CET®43 connection can handle more torque than the threadsalone could handle.

Recut

As known to one skilled in the art, as threads become used or damaged,they may be recut. When recut, the remaining tong space is reduced. TheCET®43 Threads permit one or more, recuts, while maintaining asufficient tong space. In an embodiment disclosed, several recuts may bemade, while maintaining a 9″-12″ tong space.

Embodiments

In the preceding description, for purposes of explanation, numerousdetails are set forth in order to provide a thorough understanding ofthe embodiments. However, it will be apparent to one skilled in the artthat these specific details are not required. In other instances,well-known structures and components are shown in general form in ordernot to obscure the understanding.

The above-described embodiments are intended to be examples only.Alterations, modifications and variations can be effected to theparticular embodiments by those of skill in the art. The scope of theclaims should not be limited by the particular embodiments set forthherein, but should be construed in a manner consistent with thespecification as a whole.

What is claimed is:
 1. A method comprising: providing a tubular havingan NC46 box connection and an NC46 pin connection; reducing a box outerdiameter of the NC46 box connection and enlarging a box inner diameterof the NC46 box connection to provide a prepared box connection;applying a box premium thread to the prepared box connection; reducing apin outer diameter of the NC46 pin connection and enlarging a pin innerdiameter of the NC46 pin connection to provide a prepared pinconnection; and applying a pin premium thread to the prepared pinconnection, wherein the tubular is provided with a box premiumconnection and a pin premium connection.
 2. The method of claim 1,wherein the box premium thread comprises a CET®43 box thread, whereinthe pin premium thread comprises a CET®43 pin thread, and wherein thebox premium connection and the pin premium connections are CET®43connections.
 3. The method of claim 2, further comprising heating ahardband portion of the NC46 box connection to about 950 degreesFahrenheit prior to reducing the outer diameter.
 4. The method of claim2, further comprising phosphating the CET®43 connections.
 5. The methodof claim 4, further comprising applying a make and break process to theCET®43 connections.
 6. The method of claim 2, wherein the CET®43connections have an outer diameter of about 5.375″ and wherein theCET®43 connections have an inner diameter of about 3″.
 7. The method ofclaim 2, wherein the CET®43 box threads have a pitch of about 0.25″ (4TPI), an angle of about 60 degrees, a crest to root height of about0.092500″, a taper of about 1.5 in/ft, a crest width of about 0.067″,and a root width of about 0.076″.
 8. The method of claim 2, wherein theCET®43 pin threads have a pitch of about 0.25″ (4 TPI), an angle ofabout 60 degrees, a crest to root height of about 0.092504″, a taper ofabout 1.5 in/ft, a crest width of about 0.076″, and a root width ofabout 0.067″.
 9. The method of claim 2, wherein the tubular ispreviously used or is reconditioned.
 10. The method of claim 2, furthercomprising performing a wellbore operation using the tubular havingCET®43 connections.
 11. The method of claim 10, wherein the wellboreoperation comprises horizontal drilling or hydraulic fracturing or both.12. A method of converting a tubular having NC46 connections to CET®43connections, comprising: providing the tubular, having an NC46 boxconnection and an NC46 pin connection; heating a hardband portion of theNC46 box connection to about 950 degrees Fahrenheit and reducing a boxouter diameter of the NC46 box connection; enlarging a box innerdiameter of the NC46 box connection, wherein a prepared box connectionis provided; applying a CET®43 box thread to the prepared boxconnection, wherein the CET®43 threads have a pitch of about 0.25″ (4TPI), an angle of about 60 degrees, a crest to root height of about0.092500″, a taper of about 1.5 in/ft, a crest width of about 0.067″,and a root width of about 0.076″; reducing a pin outer diameter of theNC46 pin connection; enlarging an inner diameter of the pin connection,wherein a prepared pin connection is provided; and applying a CET®43 pinthread to the prepared pin connection, wherein the CET®43 threads have apitch of about 0.25″ (4 TPI), an angle of about 60 degrees, a crest toroot height of about 0.092504″, a taper of about 1.5 in/ft, a crestwidth of about 0.076″, and a root width of about 0.067″.
 13. The methodof claim 12, wherein the CET®43 connections have an outer diameter ofabout 5.375″ and wherein the CET®43 connections have an inner diameterof about 3″.